xy>0,证|y÷x+x÷y|≥2（提示,利用（a+b)^2≥0变形）快一点------------------------急

xy>0,证|y÷x+x÷y|≥2（提示,利用（a+b)^2≥0变形）快一点------------------------急 (x^2-xy)y÷y-x/xy怎么做? (x+y)^2/y^2-xy÷[-y^2+xy/(x-y)^2,x=0,y=根号10 (xy-x²)÷(x²-2xy+y²/xy)×（x-y/x²） x-y/x²÷x²-2xy+y²/xy*（xy-x²） 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 计算：(x+y/x-y)÷(xy+x^2) 计算（xy-y^2)÷x-y/xy 【x(xy-xy)-y(x-xy)】÷3xy 谁帮我化简：[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]÷xy 已知y-2x=0,求代数式[（x+y）（x-xy+y）]÷[（x+xy+y）（x-y）]的值? （x-y/x+y）^2÷（y-x/x^2+2xy+y^2)^2 (3xy)^2÷(-xy)+(x-2y)^2-(x+2y)(x-2y) 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 √x+y-3+/xy+x+y-2/＝0,求x÷y+y÷x的值. x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² [(x+y)^2-(x-y)^2]÷(1/2xy) 化简：[(x+y)²-(x-y)²]÷2xy